1. Field of the Invention
This invention relates to an adjustable size annular retaining assembly suitable particularly, but not exclusively, for use in confined spaces.
2. Discussion of Prior Art
In many engineering constructions, such as aircraft wings, components are assembled together in a manner which leaves some components such as fasteners and retaining rings in confined spaces which are difficult to access for maintenance and inspection. Therefore when such components are required to be replaced, it can result in a lengthy and costly procedure, often requiring the additional removal of nearby, but unrelated components.
There is thus a need for a retaining assembly whose size is adjustable, so as to permit removal and fitting from and through confined spaces without disturbing surrounding and unrelated components.
According to the present invention there is provided an adjustable size annular retaining assembly for use in a confined space, including at least two substantially annular substantially rigid segments and means for pivotably interconnecting the segments in end to end relationship so that when the segments are pivotally interconnected at all but a single pair of adjoining segment ends the assembly can be contracted to a reduced size condition for insertion through or into or removal through or from a confined space, and expanded into a desired annular size condition for pivotal interconnection of said non-connected pair of adjoining segment ends.
Preferably said at least two substantially annular substantially rigid segments are each arcuate in profile, of substantially identical projected diameter and of suitable circumferential length so as to form an annular ring in said expanded desired annular size condition.
Conveniently, in said reduced size condition, the segment pivotably interconnecting means are such, that when the segments are pivotably interconnected at all but a single pair of adjoining segment ends, as to permit, movement, in the case of two segments, between the two segments at the interconnected segment ends in and/or out of the plane of said segments, and in the case of three or more segments, between adjoining segments, at the interconnected segment ends in the plane of the segments.
Advantageously the assembly has two segments, and the segment pivotably interconnecting means includes a lug formation at each end of a first of the two segments, an axially extending internally threaded bore in one end and a lug formation at the other end of a second of the two segments, a connecting rod with a lug formation at one end thereof and which other end thereof is externally threaded for engagement with the correspondingly threaded bore of the second of said segments, for providing said out of plane movement between the two segments by relative rotation along the thread length between the connecting rod and second of said segments, said lug formations each having at least one bore therethrough transverse to the plane of the segments and rod respectively, and two or more interconnecting pins, insertable into the transverse bores, when axially aligned, of the lug formation of the connecting pin and one lug formation of the first of said segments, and of the other lug formation of the first of said segments and the adjoining lug formation of the second of said segments, for providing said in plane movement between the two segments by pivoting of said lug formations about their associated interconnecting pins.
Preferably the first segment lug formations include at one end a forked portion, with the associated transverse bore extending therethrough, for engagement with the adjoining connecting rod lug formation, and at the other end a fork element which is offset relative to a fork element forming the lug formation of the second segment for pivotal interconnection therewith.
Conveniently, the assembly includes pin retaining means for, when said assembly is in the expanded desired annular size condition with the interconnecting pins in the axially aligned transverse bores, engaging ends thereof so as to retain the pins in their bores.
Advantageously the pin retaining means includes at least two interfaces, provided by at least two substantially annular plates, removably attachable to the segments in the expanded desired annular size condition, and/or by adjoining housings when the assembly is operatingly associated therewith.
Preferably at least one of said interconnecting pins is a threaded shank bolt and the transverse bore of the lug formation of the second of two segments is correspondingly threaded.
Conveniently the assembly has three or more segments, and the segment pivotably interconnecting means includes a lug formation at each end of each segment, each of which formations has a bore therethrough transverse to the plane of the segments, and three or more interconnecting pins, each insertable into the transverse bores, when axially aligned, of two adjoining segment end lug formations, for providing said in plane movement between adjoining segments by pivoting of said lug formations about the associated interconnecting pin.
Advantageously each lug formation includes at least one fork element, each having one of the associated transverse bores extending therethrough and being offset relative to the adjoining lug formation fork element or elements for pivotal interconnection therewith.
Preferably each substantially annular segment is internally grooved throughout its length to provide an internal channel therealong.
Conveniently the assembly includes a substantially annular retaining spring for removable location in said internal channel when said assembly is in the expanded desired annular size condition with the interconnecting pins in the axially aligned transverse bores to engage adjacent ends of the pins and thus retain them in said bores.
Advantageously the assembly includes pin retaining means for engaging the pin ends remote from the ends engaged by the spring.
Preferably the pin retaining means is an interface provided either by a substantially annular plate, removably attachable to the segments in the expanded desired annular size condition, or by an adjoining housing when the assembly is operatingly associated therewith.
Conveniently each substantially annular segment has a threaded surface so as to provide, in the expanded desired annular size condition of the assembly, a continuous or part continuous thread for receiving a threaded part to be removably connected to the assembly.
Advantageously the threaded surface is provided on an inner annular face of each substantially annular segment.
Preferably one or more of the substantially annular segments has a locating key on an outer annular face thereof, for engagement, when said assembly is inserted into an external housing and assembled into said expanded desired annular size condition, with one or more corresponding grooves in said housing, thereby retaining said assembly in a fixed axial position while the threaded part initially engages with the thread surface of the substantially annular segments.
Conveniently one or more of the substantially annular segments has a tang on an outer annular face thereof, for engagement, when said assembly is inserted into an external housing and assembled into said expanded desired annular size condition, with one or more corresponding grooves in said housing, thereby providing resistance against a reactive moment induced by engagement of the threaded part into the thread surface of the substantially annular segments, so as to maintain a fixed polar position.
Preferably the assembly has five substantially annular substantially rigid segments.
According to a further aspect of the present invention there is provided an aircraft wing and landing gear assembly having at least one landing gear structure carried on a pintle in a bearing in a bore in a pintle housing in the wing, and including an adjustable size annular retaining assembly as hereinbefore described, in the expanded desired annular size condition, with the pintle and pintle housing to retain said bearing in the bore, and for insertion or removal through the bore in the reduced size condition.